A circuit breaker of the general type described in the "Field of the Invention" is known from German Pat. No. 1,463,115, wherein the latching element is formed of two legs at an angle to one another and extending diagonally with respect to the central axis of the pushbutton, said legs being part of a curved metal plate fastened to the bimetallic strip. When the pushbutton is depressed into the switch housing, the contact bridge is guided smoothly by the one sloping leg of the metal plate until it locks. One end of the contact bridge rests against the other sloping leg of the metal plate after locking. The slopes make it possible to pull the pushbutton out of the "on" position again, whereby the corresponding end of the contact bridge slides along the metal plate and bends the bimetallic strip outward in such manner that the locking element releases the contact bridge. The disadvantage of this is that it becomes increasingly more difficult to pull the pushbutton out to release the switch as the contact bridge is held more firmly in its "on" position. This also means that as the force required to release the switch decreases, the force holding the contact bridge in the "on" position decreases, so that there is a danger that the switch can open inadvertently as a result of vibration. In addition, when installing a number of switches, it is necessary to have a greater lateral spacing, since the pushbutton must be surrounded by the fingers to pull it out, and this requires more room.
Circuit breakers are also known in which a special pushbutton is provided for manual shutoff. The arragement of two separate pushbuttons, however, makes the installation of such switches more difficult, since two holes must be provided in the trim plate.